Abstract: Aimed at the problems of great deformation force and hard corner filling in cold extrusion of spur gear, a geometry model of the streamline female die of spur gear is constructed, based on which numerical simulation of cold extrusion of spur gear is conducted. The results indicate that the streamline female die is effective in improving metal filling in corner under small deformation force. By analyzing the influence of different blank magnifying radius (namely

) on female die shape and deformation mode in the simulation process, the parameter value of  for a most optimized model is found through numerical simulation of different female dies.

Key words: mechanical manufacture, parameter optimization, numerical simulation, spur gear